Materials for Energy Applications
Catalysts for
Renewable Hydrogen & Oxygen from Water
Carbon Dioxide to Fuels
Hydrocarbon Oxidation
Charles Dismukes
http://chem.rutgers.edu/dismukes_charles
June 2012
Intellectual Property
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M4O4-cubane Type Catalysts, US Patent: 6,316,653
G.C. Dismukes and W.F. Ruettinger
M4O4-cubane Type Catalysts, US Patent: 6,803,474
G.C. Dismukes and W.F. Ruettinger
Membranes and Photo-electrochemical Devices for Carbon-Neutral
Renewable Hydrogen Generation from Water,
US Provisional Patent 60/896841
G.C. Dismukes, G.F. Swiegers, L. Spiccia and R. Brimblecombe
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Spinel Catalysts for Water and Hydrocarbon Oxidation
US Provisional Patent 61/358292
G.C. Dismukes and M. Greenblatt
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“High efficiency bubble-free electrolyzer for energy storage and
renewable hydrogen from water”
ARPA-E invited application (pending)
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”Green” Synthesis: Chlorine Dioxide from Sustainable Feedstocks”
Noble Metal Free Bioinspired Electro-catalysts for Water Oxidation
Photosynthetic
Water oxidation center
•3 billion years evolution refinement
•TOF = 500 s-1
•TON > 106
Organometallic Molecular
“cubes” [Mn4O4(R2PO2)6 ]+
Co4O4(Ac)4(Py)4
O2 Evolved (umol)
Inorganic solid
Spinel Nanoparticles :
Mn3O4 , Co3O4
1
H2O  O2
0.8
0.6
0.2
Mn3O4
0
50 nm
Co3O4
Light
0.4
0
2
4
6
Time (min)
8
H2O  O2
Inorganic solid
Delithiated Spinels :
LiMn2O4 λ-MnO2
A2B2O4  AB2O4
10
Synthetic methods for nanomaterials
Sol Gel
Hydrothermal
Solid State
Manganese oxide polymorphs
α-MnO2
“Cryptomelanetype”
λ-MnO2
Delithiated Spinel
β-MnO2
δ-MnO2
Pyrusolite “Birnessite-type”
LiMn2O4
Spinel
Mn2O3
Bixbyite
R-MnO2
Ramsdellite
Mn3O4
Hausmannite
Controlling both atomic & long range
(hierarchical) structure
PXRD for crystal
structure
SEM for morphology
Catalytic potential for water oxidation
Mn2O3
λ-MnO2
β-MnO2
LiMn2O4, δ-MnO2,
R-MnO2, α-MnO2
Co4O4 Molecular “Cubane” Catalyst
Co4O4Py4Ac4
McCool, JACS 2011
Nick McCool
David Robinson
Co(NO3)2
+ Py
+ Na Acetate
+ H2O2
O2 ↑ via RuII Photooxidation
pH 7.0
1
pH 5.8
pH 4.8
Catalyst
TOF (s-1) TON Oxidant
1
Co4O4(py)4(Ac)4
2.0x10-2
Py + Ac
Mn4O4(MeOPh2PO2) 2.4x10-4
in Nafion/GC
>40* RuIII(bpy)33+
>103
GC @1.2 V
Ru(bpy)32+
1 + Ru(bpy)32+
Solar Fuel Cell
Multi-layer Cubane/Nafion Performance at no external potential
Gen 2 Water Splitting via Mn4O4L6 Cubanes
H2O  O2 + 4e- + 4H+
Organometallic
Molecular “cubium”
Demonstrated Performance*:
•Photocurrent = 0.5 mA/cm2 at 1.3V DSSC
at 1 sun (275-750 nm)
•Peak Solar-to-O2 Eff. η = 1.1% (0.1 sun)
•TOF = 1.4 mol O2/cm2 h
•TOF’= 0.5 mol O2 /mol Mn h
* Nafion limits catalyst ~ 6x10-2 catalysts/ 103 Å3
Future Anode Improvements:
•↑Cubium loading, 3D-electrodes
•↓diffusion: covalent attachment
•↓Eliminate Light pre-activation
•↓Energy barrier (Eact)
•Bimetallic cubanes AB3O4
•Replace Nafion: solid acids
Brimblecombe et al (2009) Dalton Perspsective. ; Dismukes et al. (2009) Acc. Chem Res.
Brimblecombe et al. (2010) JACS; Brimblecombe et al. (2010) ChemSusChem , 3, 1–5
Bioinspired Catalyst for Water Oxidation
Crystal structure transformation of lithium cobalt
oxides Only the cubic polymorph is an active water
oxidation catalyst
Gardner, Robinson, Smith, Go, Greenblatt, Dismukes (2012) Angew Chemie, 51, 1616.
Pill millipede: http://photos.wildmadagascar.org/images/pill_millipede_ball_0142.shtml
Bulk electrolysis (1.2 V vs Ag/AgCl,
pH 7.2, 0.1 M phosphate buffer) on
ITO membrane electrode assemblies
(MEAs)
cubic-Li2Co2O4 (black)
layered-LiCoO2 (red).
®Nafion-only control
(blue).
Sol-Gel Nanophase TMO Preparation*
LiNO3 + Co(NO3)2 + CH4N2O + C6H8O7
A
Solvent Evaporation,
- NH4NO3, NH4(citrate)
LiCo(citrate) precursor
400 °C,
2 hours
- CO2
B
A
B
700 °C,
1-2
hours
C
C
* With Prof. Martha Greenblatt
Li2Co2O4 Cubic
LiCoO2 Layered
Water Oxidation catalyzed
by two LiCoO2 polymorphs
400 °C
O2
per cobalt
500 °C
600 °C
Calcination
Temperature
BET Surface
area (m2/g)
400 °C
500 °C
600 °C
700 °C
56.19
26.30
21.83
14.24
Gardner et al (2012) ACI
Average
particle size
(nm)
50
50
75
100
O2 per
BET
surface
area
Only the spinel LiCoO2 has Co4O4 cubes which is
essential for catalysis
Layered (R-3m) LiCoO2
Spinel
Layered
Spinel (Fd-3m) LiCoO2
Co4O4
Overpotential for water electrolysis:
LiMM’O4 binary spinels (M = Co, Mn) and
spinel λ-Mn2O4 consistently outperform
Platinum as OER catalyst
Water oxidation overpotential (HHV) determined at 10 mA/cm2 in 0.1 M Na2SO4 solution
(unbuffered) at pH 7 of OER Catalysts. The MEA solution consisted of 5 mg catalyst, 1.5
mg acetylene black, & 0.5 mL neutral Nafion. 3 µL MEA solutions were dropcast on the
electrode & dried at 25 oC for 1 h followed by 120C for 20 min. The reference was
Ag/AgCl with a large Pt wire/mesh counter electrode.
Membrane coated electrodes
Suspended Spinel
Catalysts
Nafion membrane with
conductive carbon particles
allowing proton and electron
flow
Glassy Carbon Electrode
Estevez, L. et. Al. Journal of the American Chemical Society 2011 133 (16), 6122-6125
Replacing Nafion:Fuel Cells & Electrolyzers
Polystyrene
sulfonic acid
Nafion
$$$
$
4.5
0.1 M NaOH
0.9 V vs.
Ag/AgCl
Current density (mA/cm2)
4
3.5
3
2.5
2
Nafion
1.5
With
catalyst
PSSA
1
Without
catalyst
0.5
0
0
100
200
300
Time (sec)
400
500
600
Rutgers infrastructure used for these projects:
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Institute for Advanced Materials, Devices and Nanotechnology
(IAMDN),
Department of Chemistry
Materials Science and Engineering Dept.
Nanofabrication Laboratory;
Microelectronics fabrication and characterization (MERL clean room)
Surface Characterization Laboratory
Thermal Analysis Laboratory;
X-ray Scattering Analysis
Electron Microscopy Laboratory;
Instrumentation for particle and pore sizes, patterning, lithography,
printing
BET Nitrogen adsorption analyzer (NOVA 2000 BET)
Rutgers Collaborator
Princeton Team Rutgers Team
Martha Greenblatt
Wolfgang RuettingerClyde Cady
David Robinson
Yong Bok Go
Tom Carrell
Rob Brimblecombe Graeme Gardner
Collaborators
Paul Smith
Nick McCool
John Sheats
Monash U.
John
Sheats
Patrick Baesjou
Leone Spiccia
Marcelo Maneiro
Rob Brimblecombe
Princeton Collaborators:
Masayuki Yagi
Alan Bond
Steve Bernasek
Jian-Zhong Wu
Kurt Wolf
Ying Yu
Univ. Wollongong
Roberto
Car
Greg Felton
Gerry Swiegers
Filippo DeAngelis
Johanna Scarino George McLendon
Matt Lin
Joe Dennes
$
Emilie Bourles
NIH-GM, AFOSR, DOE
Shari Cohen
Lemberg Award, Fullbright